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May be port leak when use handleNewUDPFlow in Network Extension
When handleNewUDPFlow in NETransparentProxyProvider is used to handle UDP data from port 53, at the same time, run the script continuously to execute nslookup or dig, about tens of thousands of times later, the nslookup shows the error "isc_socket_bind: address not available". So I check the system port status, and find all of the ports from 49152 to 65535 are occupied. The number of net.inet.udp.pcbcount is also very high. net.inet.udp.pcbcount: 91433 Then I made the following attempts: handleNewUDPFlow function return false directly, the nslookup script runs with no problems. I write a simple network extension that use handleNewUDPFlow to reply the mock data directly, and only hijack the UDP data from my test program (HelloWorld-5555). My network exntension code: override func handleNewUDPFlow(_ flow: NEAppProxyUDPFlow, initialRemoteEndpoint remoteEndpoint: NWEndpoint) -> Bool { guard let tokenData = flow.metaData.sourceAppAuditToken, tokenData.count == MemoryLayout<audit_token_t>.size else { return false } let audit_token = tokenData.withUnsafeBytes { buf in buf.baseAddress?.assumingMemoryBound(to: audit_token_t.self).pointee } let pid = audit_token_to_pid(audit_token ?? audit_token_t()) if (!flow.metaData.sourceAppSigningIdentifier.starts(with: "HelloWorld-5555")) { return false } Logger.statistics.log("handleNewUDPFlow \(remoteEndpoint.debugDescription, privacy: .public) \(flow.hash), pid:\(pid), \(flow.metaData.sourceAppSigningIdentifier, privacy: .public)") flow.open(withLocalEndpoint: nil) { error in if let error { os_log("flow open error: %@", error.localizedDescription) return } flow.readDatagrams { data_grams, remote_endpoints, read_err in guard let read_data_grams = data_grams, let read_endpoints = remote_endpoints, read_err == nil else { os_log("readDatagrams failed") flow.closeReadWithError(nil) flow.closeWriteWithError(nil) return } let mockData = Data([0x01,0x02,0x03]) let datagrams = [ mockData ] guard let remoteEnd = remoteEndpoint as? NWHostEndpoint else { os_log("Not the NWHostENdpoint") flow.closeReadWithError(nil) flow.closeWriteWithError(nil) return } let endpoints = [ NWHostEndpoint(hostname: remoteEnd.hostname, port: remoteEnd.port) ] flow.writeDatagrams(datagrams, sentBy: endpoints) { error in if let error { os_log("writeDatagrams error: %@", error.localizedDescription) } os_log("writeDatagrams close") flow.closeReadWithError(nil) flow.closeWriteWithError(nil) } } } return true } My test program code: void send_udp() { int sockfd; struct sockaddr_in server_addr; char buffer[BUFFER_SIZE]; int bytes_sent; // create socket if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { perror("socket create failed"); exit(EXIT_FAILURE); } struct sockaddr_in local_addr; memset(&local_addr, 0, sizeof(local_addr)); local_addr.sin_family = AF_INET; local_addr.sin_addr.s_addr = htonl(INADDR_ANY); local_addr.sin_port = htonl(0); // bind if (bind(sockfd, (struct sockaddr*)&local_addr, sizeof(local_addr)) < 0) { printf("IPV4 bind errno:%d\n", errno); close(sockfd); return; } // server addr memset(&server_addr, 0, sizeof(server_addr)); server_addr.sin_family = AF_INET; server_addr.sin_port = htons(SERVER_PORT); server_addr.sin_addr.s_addr = inet_addr(SERVER_IP); // send & recv strcpy(buffer, "Hello, UDP server!"); bytes_sent = sendto(sockfd, buffer, strlen(buffer), 0, (struct sockaddr *)&server_addr, sizeof(server_addr)); if (bytes_sent < 0) { perror("sendto failed"); close(sockfd); exit(EXIT_FAILURE); } printf("sendto ok\n"); char recvbuf[128] = {0}; socklen_t len = sizeof(server_addr); int sz = recvfrom(sockfd, recvbuf, sizeof(recvbuf), MSG_WAITALL, (struct sockaddr *) &server_addr, &len); printf("recv sz: %d\n", sz); close(sockfd); return; } int main() { send_udp(); return 0; } 2.1 When I use bind in my program, after the program running tens of thousands of times, the ports are exhausted, and nslookup return the error "isc_socket_bind: address not available". The case looks like running the nslookup script, because the nslookup will call the bind. 2.2 When I remove the bind from my program, all the tests are go. I have made the above experiments on different systems: 13.x, 14.x, 15.x, and read the kernel source code about bind and port assignment, bsd/netinet/in_pcb.c bsd/netinet/udp_usrreq.c and find kernel will do different action for network extension by call necp_socket_should_use_flow_divert I have checked my network extension process by lsof and netstat, its sockets or flows are all closed properly. I don't know how I can avoid this problem to ensure my network extension to work long time properly. Apparently, the port exhaustion is related to the use of bind function and network extension. I doubt there is a port leak problem in system when use network extension. Hope for your help.
3
0
958
Mar ’25
XPC connection consistently invalidated on app upgrade
Hi, Our project is a MacOS SwiftUI GUI application that bundles a System Network Extension, signed with a Developer ID certificate for distribution outside of the app store. The system network extension is used to write a packet tunnel provider. The signing of the app & network extension is handled by XCode (v16.0.0), we do not run codesign ourselves. We have no issues with XPC or the system network extension during normal usage, nor when the application is installed on a user's device for the first time. The problem only arises when the user upgrades the application. I have experienced this issue myself, as have our users. It's been reported on Apple Silicon macbooks running at least macOS 15.3.2. Much like the SimpleFirewall example (which we used as a reference), we use XPC for basic communication of state between the app and NE. These XPC connections stop working when the user installs a new version of the app, with OS logs from the process indicating that the connection is immediately invalidated. Subsequent connection attempts are also immediately invalidated. Toggling the VPN in system settings (or via the app) does not resolve the problem, nor does restarting the app, nor does deleting and reinstalling the app, nor does restarting the device. The only reliable workaround is to delete the system extension in Login Items & Extensions, under Network Extensions. No device restart is necessary to garbage collect the old extension - once the extension is reapproved by the user, the XPC issue resolves itself. This would be an acceptable workaround were it possible to automate the deleting of the system extension, but that appears deliberately not possible, and requiring our users to do this each time they update is unreasonable. When the upgraded app is opened for the first time, the OSSystemExtensionRequest request is sent, and the outcome is that the previously installed system network extension is replaced, as both the CFBundleVersion and CFBundleShortVersionString differ. When this issue is encountered, the output of systemextensionsctl list shows the later version is installed and activated. I've been able to reproduce this bug on my personal laptop, with SIP on and systemextensionsctl developer off, but on my work laptop with SIP off and systemextensionsctl developer on (where the network extension is replaced on each activation request, instead of only when the version strings differ), I do not encounter this issue, which leads me to believe it has something to do with the notarization process. We notarize the pkg using xcrun notarytool, and then staple to the pkg. This is actually the same issue described in: https://developer.apple.com/forums/thread/711713 https://developer.apple.com/forums/thread/667597 https://developer.apple.com/forums/thread/742992 https://developer.apple.com/forums/thread/728063 but it's been a while since any of these threads were updated, and we've made attempts to address it off the suggestions in the threads to no avail. Those suggestions are: Switching to a .pkg installer from a .dmg As part of the .pkg preinstall, doing all of the following: Stopping the VPN (scutil --nc stop), shutting down the app (using osascript 'quit app id'), and deleting the app (which claims to delete the network extension, but not the approval in Login Items & Extensions remains??), by running rm -rf on the bundle in /Applications As part of the .pkg postinstall: Forcing macOS to ingest the App bundle's notarization ticket using spctl --assess. Ensuring NSXPCListener.resume() is called after autoreleasepool { NEProvider.startSystemExtensionMode() } (mentioned in a forum thread above as a fix, did not help.) One thing I'm particularly interested in is the outcome of this feedback assistant ticket, as I can't view it: FB11086599. It was shared on this forum in the first thread above, and supposedly describes the same issue. I almost find it hard to believe that this issue has been around for this many years without a workaround (there's system network extension apps out there that appear to work fine when updating, are they not using XPC?), so I wonder if there's a fix described in that FB ticket. Since I can't view that above feedback ticket, I've created my own: FB17032197
5
0
416
Jun ’25
Crash heppen when i set to false to the usesClassicLoadingMode in URLSessionConfiguration
when i set the flag false to the usesClassicLoadingMode, then the application is getting crashed Ex: let config = URLSessionConfiguration.default if #available(iOS 18.4, *) { config.usesClassicLoadingMode = false } Crash log : *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[__NSCFBoolean objectForKeyedSubscript:]: unrecognized selector sent to instance 0x1f655c390' *** First throw call stack: (0x188ae52ec 0x185f69a7c 0x188b4f67c 0x1889fcb84 0x1889fc4f0 0x191393bc8 0x1889ec8a0 0x1889ec6e4 0x191393ad0 0x191344dac 0x191344b58 0x107cfa064 0x107ce36d0 0x191343fcc 0x1891b3b18 0x1892dae58 0x189235c60 0x18921e270 0x18921d77c 0x18921a8ac 0x107ce0584 0x107cfa064 0x107ce891c 0x107ce95d8 0x107ceabcc 0x107cf5894 0x107cf4eb0 0x212f51660 0x212f4e9f8) terminating due to uncaught exception of type NSException
1
0
154
Apr ’25
BSD socket APIs and macOS entitlements
I am looking for inputs to better understand MacOS entitlements. I ask this in context of OpenJDK project, which builds and ships the JDK. The build process makes uses of make tool and thus doesn't involving building through the XCode product. The JDK itself is a Java language platform providing applications a set of standard APIs. The implementation of these standard APIs internally involves calling platform specific native library functions. In this discussion, I would like to focus on the networking functions that the implementation uses. Almost all of these networking functions and syscalls that the internal implementation uses are BSD socket related. Imagine calls to socket(), connect(), getsockopt(), setsockopt(), getaddrinfo(), sendto(), listen(), accept() and several such. The JDK that's built through make is then packaged and made available for installation. The packaging itself varies, but for this discussion, I'll focus on the .tar.gz archived packaging. Within this archive there are several executables (for example: java, javac and others) and several libraries. My understanding, based on what I have read of MacOS entitlements is that, the entitlements are set on the executable and any libraries that would be loaded and used by that executable will be evaluated against the entitlements of the executable (please correct me if I misunderstand). Reading through the list of entitlements noted here https://developer.apple.com/documentation/bundleresources/entitlements, the relevant entitlements that an executable (like "java") which internally invokes BSD socket related syscalls and library functions, appear to be: com.apple.security.network.client - https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.security.network.client com.apple.security.network.server - https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.security.network.server com.apple.developer.networking.multicast - https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.developer.networking.multicast Is my understanding correct that these are the relevant ones for MacOS? Are there any more entitlements that are of interest? Would it then mean that the executables (java for example) would have to enroll for these entitlements to be allowed to invoke those functions at runtime? Reading through https://developer.apple.com/documentation/bundleresources/entitlements, I believe that even when an executable is configured with these entitlements, when the application is running if that executable makes use of any operations for which it has an entitlement, the user is still prompted (through a UI notification) whether or not to allow the operation. Did I understand it right? The part that isn't clear from that documentation is, if the executable hasn't been configured with a relevant entitlement, what happens when the executable invokes on such operation. Will the user see a UI notification asking permission to allow the operation (just like if an entitlement was configured)? Or does that operation just fail in some behind the scenes way? Coming back to the networking specific entitlements, I found a couple of places in the MacOS documentation where it is claimed that the com.apple.developer.networking.multicast entitlement is only applicable on iOS. In fact, the entitlement definition page for it https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.developer.networking.multicast says: "Your app must have this entitlement to send or receive IP multicast or broadcast on iOS. It also allows your app to browse and advertise arbitrary Bonjour service types." Yet, that same page, a few lines above, shows "macOS 10.0+". So, is com.apple.developer.networking.multicast entitlement necessary for an executable running on MacOS which deals with multicasting using BSD sockets? As a more general comment about the documentation, I see that the main entitlements page here https://developer.apple.com/documentation/bundleresources/entitlements categorizes some of these entitlements under specific categories, for example, notice how some entitlements are categorized under "App Clips". I think it would be useful if there was a category for "BSD sockets" and under that it would list all relevant entitlements that are applicable, even if it means repeating the entitlement names across different categories. I think that will make it easier to identify the relevant entitlements. Finally, more as a long term question, how does one watch or keep track of these required entitlements for these operations. What I mean is, is it expected that application developers keep visiting the macos documentation, like these pages, to know that a new entitlement is now required in a new macos (update) release? Or are there other ways to keep track of it? For example, if a newer macos requires a new entitlement, then when (an already built) executable is run on that version of macos, perhaps generate a notification or some kind of explicit error which makes it clear what entitlement is missing? I have read through https://developer.apple.com/documentation/bundleresources/diagnosing-issues-with-entitlements but that page focuses on identifying such issues when a executable is being built and doesn't explain the case where an executable has already been shipped with X entitlements and a new Y entitlement is now required to run on a newer version of macos.
13
0
928
Mar ’25
Access BSSID MacOS
I don't understand what permissions need to be given for this code to operate. I cannot seem to work out why I'm not able to see a BSSID. I think I've given sandbox the appropriate permissions AND I've added some to the Target Properties for good measure. Yet, cannot get BSSID. import SwiftUI import CoreWLAN import CoreLocation struct ContentView: View { @State private var currentBSSID: String = "Loading..." var body: some View { VStack { Image(systemName: "globe") .imageScale(.large) .foregroundStyle(.tint) Text("Current BSSID:") Text(currentBSSID) } .padding() .onAppear(perform: fetchBSSID) } func fetchBSSID() { if let iface2 = CWWiFiClient.shared().interface() { print("✅ Found Wi-Fi interface: \(iface2.interfaceName ?? "nil")") } else { print("❌ No Wi-Fi interface found") } if let iface = CWWiFiClient.shared().interface(), let bssid = iface.bssid() { currentBSSID = bssid } else { currentBSSID = "Not connected" print("✅ BSSID: \(currentBSSID)") } } } #Preview { ContentView() } Output - WifI interface is found but BSSID is not found.
2
0
206
Apr ’25
Real-time audio application on locked device
I would like to inquire about the feasibility of developing an iOS application with the following requirements: The app must support real-time audio communication based on UDP. It needs to maintain a TCP signaling connection, even when the device is locked. The app will run only on selected devices within a controlled (closed) environment, such as company-managed iPads or iPhones. Could you please clarify the following: Is it technically possible to maintain an active TCP connection when the device is locked? What are the current iOS restrictions or limitations for background execution, particularly related to networking and audio? Are there any recommended APIs or frameworks (such as VoIP, PushKit, or Background Modes) suitable for this type of application?
1
0
191
Jun ’25
Network Service Order for IoT Ethernet device
I am making a USB attached IoT device that follows the Matter approach to connectivity (IP/mDNS/DHCP). I am having conflicts with it as it appears to MacOS as an Ethernet adapter and this is causing it to be assigned as a "default" route, interfering with routing when my Mac is connected to NAT based WiFi. I'd like to be able to hint to MacOS & iPadOS that this is not a routable private network, the subnet should be respected and a default route should not be assigned to it, otherwise the order of the device connection is used by the IP routing tables and I am concerned my non-routable private network will initialize before Wifi and block NAT based internet connectivity. How can I hint to MacOS/iPadOS "this is not a routable private network, this is not a NAT, do not assign me a default route beyond the subnet I have provided you."
1
0
118
Apr ’25
Issues with Opening iOS Settings from App
Hi there! We are working on our SkyElectric App which is being developed in Flutter framework, where we need user to connect with the Wifi of the the inverter. We are trying to direct user to WiFi Settings page of the iOS in general settings where all the available WiFi Networks are listed but unfortunately user is being directed to App's Settings page. We are using package of app_settings and launcher. I've read that Apple changed a policy in 2019 where it restricts Apps to navigate to OS pages. Question: Could you please verify if I APPLE allows us to access the General Settings or WiFi Settings through clicking a button in our App name "Open WiFi Settings", If not then Why?
2
0
84
Apr ’25
how to register listener to `NWConnectionGroup` for QUIC
I am trying to make http3 client with Network.framework on Apple platforms. Codes that implement NWConnectionGroup.start with NWListener don't always work with warning below. I assume NWConnectionGroup.newConnectionHandler or NWListener.newConnectionHandler will be called to start connection from the server if it works. nw_protocol_instance_add_new_flow [C1.1.1:2] No listener registered, cannot accept new flow quic_stream_add_new_flow [C1.1.1:2] [-fde1594b83caa9b7] failed to create new stream for received stream id 3 so I tried: create the NWListener -> not work check whether NWConnectionGroup has a member to register or not NWListener -> not work (it doesn't have). use NWConnection instead of NWConnectionGroup -> not work Is my understanding correct? How should I do to set or associate listener with NWConnection/Group for newConnectionHandler is called and to delete wanings? What is the best practice in the case? Sample codes are below. Thanks in advance. // http3 needs unidirectional stream by the server and client. // listener private let _listener: NWListener let option: NWProtocolQUIC.Options = .init(alpn:["h3"]) let param: NWParameters = .init(quic: option) _listener = try! .init(using: param) _listener.stateUpdateHandler = { state in print("listener state: \(state)") } _listener.newConnectionHandler = { newConnection in print("new connection added") } _listener.serviceRegistrationUpdateHandler = { registrationState in print("connection registrationstate") } // create connection private let _group: NWConnectionGroup let options: NWProtocolQUIC.Options = .init(alpn: ["h3"]) options.direction = .unidirectional options.isDatagram = false options.maxDatagramFrameSize = 65535 sec_protocol_options_set_verify_block(options.securityProtocolOptions, {(_: sec_protocol_metadata_t, _: sec_trust_t, completion: @escaping sec_protocol_verify_complete_t) in print("cert completion.") completion(true) }, .global()) let params: NWParameters = .init(quic: options) let group: NWMultiplexGroup = .init( to: .hostPort(host: NWEndpoint.Host("google.com"), port: NWEndpoint.Port(String(443))!)) _group = .init(with: group, using: params) _group.setReceiveHandler {message,content,isComplete in print("receive: \(message)") } _group.newConnectionHandler = {newConnection in print("newConnectionHandler: \(newConnection.state)") } _group.stateUpdateHandler = { state in print("state: \(state)") } _group.start(queue: .global()) _listener.start(queue: .global()) if let conn = _group.extract() { let data: Data = .init() let _ = _group.reinsert(connection: conn) conn.send(content: data, completion: .idempotent) }
4
0
212
Apr ’25
Use native Swift API for HTTP request with auth proxy
I'm simply trying to use a proxy to route a http request in Swift. I've tried using a URLSession Delegate but that results in the same issue with the iOS menu. proxy format: host:port:username:password When I run the code below I am prompted with a menu to add credentials for the proxy. I closed this menu inside my app and tried the function below again and it worked without giving me the menu a second time. However even though the function works without throwing any errors, it does NOT use the proxies to route the request. I've spent days on this and the only solution I found was using a NWConnection but this is super low level and now I need a shared session to manage cookies. If you want to see the NWConnection solution I made its here func averageProxyGroupSpeed(proxies: [String], completion: @escaping (Int, String) -> Void) { let numProxies = proxies.count if numProxies == 0 { completion(0, "No proxies") return } var totalTime: Int64 = 0 var successCount = 0 let group = DispatchGroup() let queue = DispatchQueue(label: "proxyQueue", attributes: .concurrent) let lock = NSLock() let shuffledProxies = proxies.shuffled() let selectedProxies = Array(shuffledProxies.prefix(25)) for proxy in selectedProxies { group.enter() queue.async { let proxyDetails = proxy.split(separator: ":").map(String.init) guard proxyDetails.count == 4, let port = Int(proxyDetails[1]), let url = URL(string: "http://httpbin.org/get") else { completion(0, "Invalid proxy format") group.leave() return } var request = URLRequest(url: url) request.timeoutInterval = 15 let configuration = URLSessionConfiguration.default configuration.connectionProxyDictionary = [ AnyHashable("HTTPEnable"): true, AnyHashable("HTTPProxy"): proxyDetails[0], AnyHashable("HTTPPort"): port, AnyHashable("HTTPSEnable"): false, AnyHashable("HTTPUser"): proxyDetails[2], AnyHashable("HTTPPassword"): proxyDetails[3] ] let session = URLSession(configuration: configuration) let start = Date() let task = session.dataTask(with: request) { _, _, error in defer { group.leave() } if let error = error { print("Error: \(error.localizedDescription)") } else { let duration = Date().timeIntervalSince(start) * 1000 lock.lock() totalTime += Int64(duration) successCount += 1 lock.unlock() } } task.resume() } } group.notify(queue: DispatchQueue.main) { if successCount == 0 { completion(0, "Proxies Failed") } else { let averageTime = Int(Double(totalTime) / Double(successCount)) completion(averageTime, "") } } } Delegate example class ProxySessionDelegate: NSObject, URLSessionDelegate { let username: String let password: String init(username: String, password: String) { self.username = username self.password = password } func urlSession(_ session: URLSession, task: URLSessionTask, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) { if challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodHTTPBasic { let credential = URLCredential(user: self.username, password: self.password, persistence: .forSession) completionHandler(.useCredential, credential) } else { completionHandler(.performDefaultHandling, nil) } } }
2
0
458
Mar ’25
connect() iOS 18.5 Developer Beta (22EF5042g)
Hello! 👋 I am noticing new failures in the iOS 18.5 Developer Beta build (22EF5042g) when calling the system call connect() (from C++ source, in network extension). When using cell/mobile data (Mint & T-Mobile) this returns with EINTR (interrupted system call) right away. When I switch over to wifi, everything works fine. Note: I have not tested on other mobile carriers; which could make a difference since T-Mobile/Mint are IPv6 networks. FWIW, this is working in the previous developer beta (18.4). Anyone have any ideas?
5
0
351
Apr ’25
iOS VPN Issue -Disconnecting VPN from Packet Tunnel Network Extension Causes Loss of Internet Connectivity
Feedback Ticket: FB13812251 Problem Statement: We are currently facing internet connectivity issue with our VPN application where we try to disconnect the VPN from the Packet Tunnel Network Extension using - (void)cancelTunnelWithError:(nullable NSError *)error. Which API to use to disconnect the VPN from Packet Tunnel as VPN app is not running such that device retains its internet connectivity as soon as VPN disconnects. Configuration: We have configured PacketTunnelProvider with the following settings: (NETunnelProviderManager *)tunnelProvider.protocolConfiguration.includeAllNetworks = YES; (NETunnelProviderManager *)tunnelProvider.protocolConfiguration.excludeLocalNetworks = NO; (NETunnelProviderManager *)tunnelProvider.protocolConfiguration.enforceRoutes = NO; These settings are applied from the VPN app and allow us to successfully establish a VPN connection, with all traffic being routed through the tunnel as expected.We are setting above properties to address local net attack. Issue we are facing: However, we encounter a problem when we attempt to disconnect the VPN from. When we call the following method from PacketTunnel network extension: (void)cancelTunnelWithError:(nullable NSError *)error Upon calling this method, the VPN disconnects as expected, but the device loses all internet connectivity and is unable to access any resources. This is not the desired behavior. Observation : Interestingly, when we call the following method from the app side. The VPN disconnects and the device retains its internet connectivity. [enabledConfig.connection stopVPNTunnel]; We would like to achieve the same behavior when disconnecting the VPN from the Network Extension. So we are looking for an API that could be called from NE without causing any internet connectivity issue. Any guidance on how to resolve this issue would be greatly appreciated.
4
0
729
Apr ’25
After Denying Local Network Permission on iOS 18, Re-granting Doesn't Allow the App to Discover Devices Over LAN for Configuration
On an iOS 18 device, after installing the application and initially denying local network permission when prompted, manually enabling this permission in the system settings does not resolve the issue. After uninstalling and reinstalling the app, although local network access is granted, the app cannot discover smart hardware devices over the local area network (LAN) or proceed with configuration. The smart hardware sends configuration data packets over the LAN, but the app fails to receive these packets. This issue persists even after another uninstall and reinstall of the app. However, rebooting the device restores normal functionality. Steps to Reproduce: Install the application on an iOS 18 device. Upon first launch, deny the request for local network permissions. Manually enable local network permissions via "Settings" &gt; [App Name]. Uninstall and then reinstall the application. Attempt to discover and configure smart hardware devices using the app. Notice that the app fails to receive configuration data packets sent by the smart hardware over the LAN. Expected Result: The application should be able to normally receive configuration data packets from smart hardware devices over the LAN and successfully complete the configuration process after obtaining local network permissions. Actual Result: Even after being granted local network permissions, the application cannot discover devices or receive configuration data packets over the LAN unless the iPhone device is rebooted. (reinstall app and obtaining local network permissions is not work too.)
3
0
313
May ’25
Question about listen on the utun interface to serve as system dns server
Hello, Recently I am trying to add stub dns server to my Network Extension (a VPN app), after some research on this forum, and since my language is C, I have the following plan: create a udp socket which use setsockopt(IP_BOUND_IF) to bound the socket to the utun if index obtained, and also bind to the address of the utun address I set(let's say 192.168.99.2), then listen on the udp port 53 which is ready to handle dns request. configure the dns server to 192.168.99.2 in the provider's Network Settings, thus iOS system will send udp query to the udp socket created in step 1, and it can then do some split dns function such as resolve using local interface (cellular or wifi), or some nameserve which will be routed to the VPN tunnel (will create new UDP socket and do IP_BOUND_IF to ensure the traffic will enter the VPN tunnel), and the result should be return to the system and then the non VPP apps. But I observer weird issue, indeed I can get the system send the dns request to the listening udp socket and I can get the result write to the system(address like 192.168.99.2:56144, the port should be allocated by the iOS system's DNS component) without any failure(I did get some error before due to I using the wrong utun if index, but fixed it later), but it seems non VPN app like browser can't get the resolved ip for domains. I want to ask is this limited by the sandbox? or any special sock opt I need to do. Thanks. PS: in the provider's network settings, all the system's traffic will be point to the utun, which means the VPN process will process all the traffic. the reason I do not set the dns server to utun peers side which is my userspace networking stack's ip (192.168.99.1) is the stack is not be able to leverage some dns libraries due to architecture issue. (it's fd.io vpp which we ported to apple platform).
7
0
172
Apr ’25
Investigating CFNetwork Crashes on Older macOS Versions
CFNetwork None CFURLResponseGetRecommendedCachePolicy None 0 CFNetwork None CFHTTPCookieStorageUnscheduleFromRunLoop None 0 CFNetwork None /_/_CFNetworkAgentMessageProcessorMain None 0 CFNetwork None CFURLDownloadCancel None 0 CFNetwork None CFURLDownloadCancel None 0 libdispatch.dylib None /_dispatch/_block/_async/_invoke2 None We've observed intermittent crashes in our production environment, exclusively affecting customers running macOS 10.15 and 11. The crash logs consistently show a stack trace involving CFHTTPCookieStorageUnscheduleFromRunLoop and CFURLDownloadCancel within the CFNetwork framework. This suggests potential issues with cookie storage management and/or URL download cancellation. Could the team please analyze these crash logs and provide insights into: The root cause of the crashes. Potential race conditions or synchronization issues. Recommendations for mitigating or resolving the problem. Your assistance in resolving this issue is greatly appreciated."
4
0
280
Mar ’25
Hide OS logs coming out of the Network framework (category: com.apple.network)
I'm establishing a connection with NWListener and NWConnection which is working great. However, if the listener disappears, a lot of logs are appearing: Is there a way to hide these logs? I'm aware of OS_ACTIVITY_MODE=disabled, but that will also hide a lot of other logs. I also know you can hide these using Xcode's filtering. I'm looking for a programmatically way to hide these completely. I'm not interested in seeing these at all, or, at least, I want to be in control. Thanks!
4
0
184
Apr ’25
Using NEVPNManager to detect VPN status and consistently returning NEVPNStatusInvalid
Hello! My app wants to disable VPN connection. I used the loadFromPreferencesWithCompletionHandler method of NEVPNManager for detection, but regardless of whether the VPN was actually connected or not, it kept returning NEVPNStatusInvalid. How should I handle this issue? NEVPNManager *vpnManager = [NEVPNManager sharedManager]; [vpnManager loadFromPreferencesWithCompletionHandler:^(NSError * _Nullable error) { if (error) { return; } NEVPNStatus status = vpnManager.connection.status; switch (status) { case NEVPNStatusInvalid: // kept returning NEVPNStatusInvalid break; case NEVPNStatusDisconnected: break; case NEVPNStatusConnecting: break; case NEVPNStatusConnected: break; case NEVPNStatusReasserting: break; case NEVPNStatusDisconnecting: break; default: break; } }];
3
0
149
Jun ’25
Memory release problem of VPN connection object
Hello, I encountered a memory management issue while developing VPN functionality and would like to seek your advice. The specific phenomenon is as follows: Problem description: After multiple calls to the 'createTCPConnectToEndpoint' and 'create UDPSessionToEndpoint' interfaces to create connection objects, the application memory continues to grow. Even if the cancel interface is immediately called to actively release the object, the memory does not fall back. 3. Confirm that there is no other code referencing these objects, but the system does not seem to automatically reclaim memory. Attempted measures: Immediately call the cancel method after creating the object, and the memory is not reduced Use tools such as Profiler to monitor memory and confirm that objects have not been released. doubt: Is this phenomenon normal? Is there a known memory management mechanism (such as cache pooling) that causes delayed release? 2. Are there any other interfaces or methods (such as release, dispose) that need to be explicitly called? Supplementary Information: Development environment: [iOS 16, 14pm] Reproduction steps: After continuously creating connection objects, the memory grows without falling back. Could you please help confirm if there are any abnormalities and the correct memory release posture. Thank you for your support!
3
0
112
May ’25
How can user allow a content filter after previously choosing "Don't Allow"?
Our enterprise product uses a content filter, normally customers deploy MDM profiles to authorise and allow the content filter to work. Some customers however do not use these profiles, requiring them to enable the system extension in System Settings and allow the content filter via the popup below. If the user selects "Don't Allow", intentionally or by mistake, there does not appear to be an mechanism for them to change their mind and allow it instead. If the user fails to enable the system extension on the first prompt, there is an option to enable if via System Settings. There doesn't seem to be a similar option if they "Don't Allow" the content filter. How can the user allow a previously denied content filter?
2
0
149
Apr ’25
NWBrowser + NWListener + NWConnection
I am seeking assistance with how to properly handle / save / reuse NWConnections when it comes to the NWBrowser vs NWListener. Let me give some context surrounding why I am trying to do what I am. I am building an iOS app that has peer to peer functionality. The design is for a user (for our example the user is Bob) to have N number of devices that have my app installed on it. All these devices are near each other or on the same wifi network. As such I want all the devices to be able to discover each other and automatically connect to each other. For example if Bob had three devices (A, B, C) then A discovers B and C and has a connection to each, B discovers B and C and has a connection to each and finally C discovers A and B and has a connection to each. In the app there is a concept of a leader and a follower. A leader device issues commands to the follower devices. A follower device just waits for commands. For our example device A is the leader and devices B and C are followers. Any follower device can opt to become a leader. So if Bob taps the “become leader” button on device B - device B sends out a message to all the devices it’s connected to telling them it is becoming the new leader. Device B doesn’t need to do anything but device A needs to set itself as a follower. This detail is to show my need to have everyone connected to everyone. Please note that I am using .includePeerToPeer = true in my NWParameters. I am using http/3 and QUIC. I am using P12 identity for TLS1.3. I am successfully able to verify certs in sec_protocal_options_set_verify_block. I am able to establish connections - both from the NWBrowser and from NWListener. My issue is that it’s flaky. I found that I have to put a 3 second delay prior to establishing a connection to a peer found by the NWBrowser. I also opted to not save the incoming connection from NWListener. I only save the connection I created from the peer I found in NWBrowser. For this example there is Device X and Device Y. Device X discovers device Y and connects to it and saves the connection. Device Y discovers device X and connects to it and saves the connection. When things work they work great - I am able to send messages back and forth. Device X uses the saved connection to send a message to device Y and device Y uses the saved connection to send a message to device X. Now here come the questions. Do I save the connection I create from the peer I discovered from the NWBrowser? Do I save the connection I get from my NWListener via newConnectionHandler? And when I save a connection (be it from NWBrowser or NWListener) am I able to reuse it to send data over (ie “i am the new leader command”)? When my NWBrowser discovers a peer, should I be able to build a connection and connect to it immediately? I know if I save the connection I create from the peer I discover I am able to send messages with it. I know if I save the connection from NWListener - I am NOT able to send messages with it — but should I be able to? I have a deterministic algorithm for who makes a connection to who. Each device has an ID - it is a UUID I generate when the app loads - I store it in UserDefaults and the next time I try and fetch it so I’m not generating new UUIDs all the time. I set this deviceID as the name of the NWListener.Service I create. As a result the peer a NWBrowser discovers has the deviceID set as its name. Due to this the NWBrowser is able to determine if it should try and connect to the peer or if it should not because the discovered peer is going to try and connect to it. So the algorithm above would be great if I could save and use the connection from NWListener to send messages over.
37
0
1.3k
Nov ’25